1. Field of the Invention
This invention relates to the handling of asphalt and more particularly to a method for placing molten asphalt in manually handleable packages for shipping to a job site.
2. Description of the Prior Art
As is well known in the art, molten asphalt is employed for various jobs in the construction industry such as for seal coating roadways, runways, and other comparatively large tasks. Molten asphalt is also used for comparatively smaller jobs such as filling cracks and expansion joints in paved surfaces, coating and/or patching roofs, and various other spot repair applications.
In the comparatively large jobs, such as the seal coating of a paved surface, where large quantities of the molten asphalt are to be used, the molten asphalt is placed in special transport trucks at the asphalt plant and delivered directly to the job site where it is transferred into heated spray applicator trunks. In some instances, the molten asphalt is mixed at the job site with special additives, such as shredded rubber, prior to being applied to the paved surface. At any rate, such a procedure must be accomplished rather rapidly to prevent cooling of the molten asphalt and to prevent unnecessary delays in equipment and manpower time. Even when this procedure is most efficiently accomplished, it is an expensive matter and utilizing such a procedure cannot be economically justified in the comparatively smaller jobs such as the hereinbefore mentioned filling of cracks and joints in paved surfaces.
Therefore, it is a common practice to place molten asphalt in manually handleable containers at a manufacturing facility and shipping the desired number of such containers when and as needed to the relatively small job sites. When the asphalt is needed at such a site, the containers are torn open and the asphalt which has since cooled and thus solidified is placed in the tank of a suitable heater/applicator mechanism, where it is heated to return it to its molten state, mixed with the additives, if desired, and utilized to accomplish the desired task.
The commonly used, and to the best of my knowledge, the only method used for placing the asphalt in manually handleable containers is in the form of an elongated conveyor system. At a first station of the prior art conveyor system, a plastic package or liner is inserted into an open corrugated cardboard box and transported by the conveyor to a second station below the outlet of a stationary molten asphalt dispensing unit. At this second station, the dispensing mechanism deposits a predetermined amount of the molten asphalt, usually about 60 pounds, in each container which is passed thereunder. After such filling, the containers are transported to a third station on the conveyor system where the asphalt filled packages and their container boxes are closed, and from there they are transported to the last station where they are manually off-loaded from the conveyor system and placed on pallets for subsequent shipping.
The prior art method described above has several drawbacks. In the first place, the off-loading and stacking tasks must be accomplished without excessive delays so as not to halt production. Therefore, the asphalt in the containers is still in the molten state when the off-loading and pallet stacking operations need to be accomplished. The molten state of the asphalt rules out the use of all but the most sophisticated mechanized equipment, and the cost of such equipment cannot be justified in operations of this sort. Therefore, the asphalt containers are manually off-loaded and stacked on the pallet, and this is a very arduous and uncomfortable job due to the weight of the asphalt containers and the heat radiating therefrom.
The second, and most serious, problem with the prior art conveyor system for containerizing asphalt involves the lack of portability of the equipment. High shipping costs dictates that a prior art conveyor system cannot be economically used to containerize asphalt for use outside of a given area. Thus, a prior art conveyor system is intermittently used in that it is normally capable of satisfying the needs of its immediate area with, for example, two days of operation per week. Providing containerized asphalt for areas outside of the immediate vicinity of an existing prior art conveyor system involves either paying the high shipping costs, or building and manning other conveyor systems which will also be intermittently operated.
Therefore, a need exists for a new and improved method for containerizing asphalt which overcomes some of the problems and shortcomings of the prior art.